Conkers

[Nory] liked when things had layers—the earth has layers, the trunk of a tree has layers, the atmosphere has layers. A conker has layers, too. It has a green spiky outer layer and a very shiny wonderful layer which is the conker itself, which is like the finest smoothest wood in a very precious table or the knob of a chair or something like that, in a great palace like Ickworth House, where the floorboards are curved. (They were somehow bent into curves with the help of steam engines, which pleased Littleguy.) And then inside that there's the growing part of the conker, which is like the nerve of the tooth. Sometimes you can find a double-conker. 'Conker' is the English way of saying horse chestnut, and it's a very good way because they can suddenly conk you on the head.

-Nicholson Baker, The Everlasting Story of Nory, 74.